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1.
Sensors (Basel) ; 24(7)2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38610462

RESUMO

With the rapid development of economic globalization and green manufacturing, traditional flexible job shop scheduling has evolved into the low-carbon heterogeneous distributed flexible job shop scheduling problem (LHDFJSP). Additionally, modern smart manufacturing processes encounter complex and diverse contingencies, necessitating the ability to address dynamic events in real-world production activities. To date, there are limited studies that comprehensively address the intricate factors associated with the LHDFJSP, including workshop heterogeneity, job insertions and transfers, and considerations of low-carbon objectives. This paper establishes a multi-objective mathematical model with the goal of minimizing the total weighted tardiness and total energy consumption. To effectively solve this problem, diverse composite scheduling rules are formulated, alongside the application of a deep reinforcement learning (DRL) framework, i.e., Rainbow deep-Q network (Rainbow DQN), to learn the optimal scheduling strategy at each decision point in a dynamic environment. To verify the effectiveness of the proposed method, this paper extends the standard dataset to adapt to the LHDFJSP. Evaluation results confirm the generalization and robustness of the presented Rainbow DQN-based method.

2.
Macromol Rapid Commun ; 45(6): e2300628, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38227809

RESUMO

A rare asymmetric bicyclic polymer containing different length of conjugated polyacetylene segments is synthesized by metathesis cyclopolymerization-mediated blocking-cyclization technique. The size of each single ring differs from each other, and the unique cyclic polymer topology is controlled by adjusting the feed ratio of monofunctional monomer to catalyst. The topological difference between linear and bicyclic polymers is confirmed by several techniques, and the visualized morphology of asymmetric bicyclic polymer is directly observed without tedious post-modification process. The photoelectric and thermal properties of polymers are investigated. This work expands the pathway for the derivation of cyclic polymers, and such unique topological structure enriches the diversity of cyclic polymer classes.


Assuntos
Polímeros , Poli-Inos , Polímero Poliacetilênico , Ciclização , Polímeros/química , Catálise
3.
Chem Commun (Camb) ; 58(27): 4340-4343, 2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-35293394

RESUMO

Conjugated polyacetylene-based monocyclic and bicyclic polymers were synthesized by blocking-cyclization metathesis polymerization using short ladderphanes as the initial motif and multi-cyclizing unit, and fully characterized to elucidate the cyclic characteristics and good photoelectric properties. Importantly, the molecular topology of rationally designed cyclic polymers was directly observed without a tedious post-modification treatment.

4.
Chem Commun (Camb) ; 58(4): 581-584, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34918016

RESUMO

Linear polymers containing pillar[5]arenes as the pendant groups were designed and synthesized via a ring-opening metathesis polymerization. Such polymers could form supramolecular brush polymers and exhibited tunable fluorescence properties based on the host-guest interactions.

5.
Molecules ; 26(8)2021 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-33920289

RESUMO

Constructing polymeric materials with stretchable and self-healing properties arise increasing interest in the field of tissue engineering, wearable electronics and soft actuators. Herein, a new type of supramolecular cross-linker was constructed through host-guest interaction between pillar[5]arene functionalized acrylate and pyridinium functionalized acrylate, which could form supramolecular polymeric material via photo-polymerization of n-butyl acrylate (BA). Such material exhibited excellent tensile properties, with maximum tensile strength of 3.4 MPa and strain of 3000%, respectively. Moreover, this material can effectively dissipate energy with the energy absorption efficiency of 93%, which could be applied in the field of energy absorbing materials. In addition, the material showed self-healing property after cut and responded to competitive guest.

6.
Entropy (Basel) ; 23(2)2021 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-33562233

RESUMO

Based on orthogonal Latin cubes, an image cryptosystem with confusion-diffusion-confusion cipher architecture has been proposed recently (Inf. Sci.2019, 478, 1-14). However, we find that there are four fatal vulnerabilities in this image cryptosystem, which leave open doors for cryptanalysis. In this paper, we propose a reference-validation inference algorithm and design screening-based rules to efficiently break the image cryptosystem. Compared with an existing cryptanalysis algorithm, the proposed method requires fewer pairs of chosen plain-cipher images, and behaves stably since different keys, positions of chosen bits and contents of plain images will not affect the cryptanalysis performance. Experimental results show that our cryptanalysis algorithm only requirespairs of chosen plain-cipher images, whererepresents the image's resolution. Comparative studies demonstrate effectiveness and superiority of the proposed cryptanalysis algorithm.

7.
Onco Targets Ther ; 13: 7447-7458, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32801767

RESUMO

BACKGROUND: Parthenolide (PT), the effective active ingredient of the medicinal plant, feverfew (Tanacetum parthenium), has been used as an anti-inflammatory drug due to its involvement in the inhibition of the NF-кB pathway. Moreover, recent studies have demonstrated the anti-tumor effect of PT in several cancers. However, the effect of PT on esophageal carcinoma remains unclear to date. In this study, we examined the inhibitory effects of PT and its underlying mechanism of action in human esophageal squamous cell carcinoma (ESCC) cells - Eca109 and KYSE-510. METHODS: The proliferation ability of Eca109 and KYSE-510 treated with PT was detected using the Cell Counting Kit-8 and colony forming assay. The Transwell assay and the wound healing assay were used to analyze the cell invasion and migration ability, respectively. The tube formation assay was used to investigate the effect of PT on tube formation of endothelial cells. The expression level of NF-кB, AP-1 and VEGF was analyzed by Western blot. RESULTS: We demonstrated that PT attenuates the proliferation and migration ability of ESCC cells in vitro and also inhibits tumor growth in the mouse xenograft model. In addition, PT exhibited anti-angiogenesis activity by weakening the proliferation, invasion and tube formation of endothelial cells in vitro and reduced microvessel density in the xenograft tumors. Further studies revealed that PT reduced the expression level of NF-кB, AP-1 and VEGF in ESCC cells. CONCLUSION: Collectively, the results of our study demonstrated that PT exerts anti-tumor and anti-angiogenesis effects possibly by inhibiting the NF-кB/AP-1/VEGF signaling pathway on esophageal carcinoma and might serve as a promising therapeutic agent for ESCC.

8.
ACS Macro Lett ; 9(1): 61-69, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35638656

RESUMO

Bacterial biofilms are troublesome in the treatment of bacterial infectious diseases due to their inherent resistance to antibiotic therapy. Exploration of alternative antibiofilm reagents provides opportunities to achieve highly effective treatments. Herein, we propose a strategy to employ self-assembled saccharide-functionalized amphiphilic metallacycles ([2+2]-Gal, [3+3]-Gal, and [6+6]-Gal) with multiple positive charges as a different type of antibacterial reagent, marrying saccharide functionalization that interact with bacteria via "sweet talking". These self-assembled glyco-metallacycles gave various nanostructures (nanoparticles, vesicles or micron-sized vesicles) with different biofilms inhibition effect on Staphylococcus aureus (S. aureus). Especially, the peculiar self-assembly mechanism, superior antibacterial effect and biofilms inhibition distinguished the [6+6]-Gal from other metallacycles. Meanwhile, in vivo S. aureus pneumonia animal model experiments suggested that [6+6]-Gal could relieve mice pneumonia aroused by S. aureus effectively. In addition, the control study of metallacycle [3+3]-EG5 confirmed the significant role of galactoside both in the self-assembly process and the antibacterial efficacy. In view of the superior effect against bacteria, the saccharide-functionalized metallacycle could be a promising candidate as biofilms inhibitor or treatment agent for pneumonia.

9.
ACS Macro Lett ; 8(12): 1588-1593, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-35619394

RESUMO

Regulating the conductivity of conducting polymers has spurred increasing studies, aiming at meeting different demands in various fields, including chemosensors, photovoltaic cells, and so on. Herein, linear pillar[5]arene-containing conjugated polymers were designed and synthesized via metathesis cyclopolymerization of pillar[5]arene-functionalized 1,6-heptadiyne. Upon addition of an ionic guest, such polymers could form inclusion complexes, of which the glass transition temperature decreased dramatically. With the aid of ionic guest and host-guest complexations between the pendant pillararenes and guest, these supramolecular materials exhibited tunable conductivity from 10-12 to 10-3 S·cm-1 at 30 °C. In addition, compared with the polymers without pendant pillar[5]arenes, such polymers showed better compatibility with the ionic guest, which could prevent the leakage of the latter one and was good for the conductivity of the material.

10.
Nat Commun ; 9(1): 5310, 2018 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-30552323

RESUMO

Ring-closure and ring-expansion techniques are the two routes for extensive synthesis of cyclic polymers. Here, we report an alternative blocking-cyclization technique referred to as the third route to prepare cyclic polymers with regulated ring size and ring number by ring-opening metathesis polymerization of di- and monofunctional monomers in a one-pot process, where the polymer intermediates bearing two single-stranded blocks are efficiently cyclized by the cyclizing unit of propagated ladderphane to generate corresponding mono-, bis-, and tricyclic polymers, and the well-defined ladderphane structure plays a crucial role in forming the cyclic topology. Monocyclic polymer is further modified via Alder-ene reaction and the cyclic molecular topology is clearly demonstrated. The diversity features of cyclic polymers are comprehensively revealed. This strategy has broken through the limitations of previous two cyclizing routes, and indeed opens a facile and popular way to various cyclic polymers by commercial Grubbs catalyst and conventional metathesis polymerization.

11.
Macromol Rapid Commun ; 37(24): 2017-2022, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27862546

RESUMO

Metathesis cyclopolymerization of mono- or bissubstituted 1,6-heptadiynes is undergone to generate the ionic polyacetylenes (iPAs) with branched 1,2,3-ttriazolium pendants, which possess relatively high intrinsic ionic conductivities of 1.4 × 10-5 -2.1 × 10-5 S cm-1 at 30 °C. The doping treatment with lithium bis(trifluoromethanesulfonyl)imide endows iPAs with enhanced ionic conductivities of 2.5 × 10-5 -4.3 × 10-5 S cm-1 . Further doping with iodine, iPAs show ionic and electronic dual conductivities of 4.5 × 10-5 -7.1 × 10-4 and 1.5 × 10-6 -4.5 × 10-6 S cm-1 , respectively. Therefore, the doped iPAs demonstrate the potential in the area of conducting polymers and polymeric electronics.


Assuntos
Poli-Inos/química , Poli-Inos/síntese química , Triazóis/química , Condutividade Elétrica
12.
Nanotechnology ; 27(11): 115603, 2016 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-27308672

RESUMO

In this paper, we report a novel method for constructing a soluble organic nanotube supported catalyst system based on single-molecule templating of core­shell bottlebrush copolymers. Various organic or metal catalysts, such as sodium prop-2-yne-1-sulfonate (SPS), 1-(2-(prop-2-yn-1-yloxy)ethyl)-1H-imidazole (PEI) and Pd(OAc)2 were anchored onto the tube walls to functionalize the organic nanotubes via copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. Depending on the 'confined effect' and the accessible cavity microenvironments of tubular structures, the organic nanotube catalysts showed high catalytic efficiency and site-isolation features. We believe that the soluble organic nanotubes will be very useful for the development of high performance catalyst systems due to their high stability of support, facile functionalization and attractive textural properties.

13.
Macromol Rapid Commun ; 37(2): 149-54, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26524109

RESUMO

In this paper, a novel synthesis of polyethylene glycol (PEG)-modified polypyrrole (PPy) nanomaterials is demonstrated by combining reversible addition-fragmentation chain transfer polymerization and oxidative polymerization. Dye molecules with a heat-labile linker are used as a model drug and covalently anchored onto the PEGlated PPy nanomaterials via "click chemistry." The strong absorption of such PPy nanomaterials in the near-infrared region endows the system excellent photothermal effect, which can be used not only as efficient photothermal agents for photothermal therapy but also good controllers of a drug-release system by retro D-A reaction.


Assuntos
Preparações de Ação Retardada/síntese química , Nanopartículas/química , Polietilenoglicóis/química , Polímeros/química , Pirróis/química , Química Click , Liberação Controlada de Fármacos , Corantes Fluorescentes/química , Ouro/química , Raios Infravermelhos , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Processos Fotoquímicos , Pirenos
14.
Chem Commun (Camb) ; 51(83): 15320-3, 2015 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-26340600

RESUMO

A new type of insulating-conductive block copolymer was synthesized by metathesis polymerization. The copolymer can self-assemble into unique nanostructures of micelles or hollow spheres. It exhibits a high dielectric constant, low dielectric loss, and high stored/released energy density due to the strong dipolar and nano-interfacial polarization contributions.

15.
Macromol Rapid Commun ; 36(16): 1492-7, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26033255

RESUMO

Pillararene-containing thermoresponsive polymers are synthesized via reversible addition-fragmentation chain transfer polymerization using pillararene derivatives as the effective chain transfer agents for the first time. These polymers can self-assemble into micelles and form vesicles after guest molecules are added. Furthermore, such functional polymers can be further applied to prepare hybrid gold nanoparticles, which integrate the thermoresponsivity of polymers and molecular recognition of pillararenes.


Assuntos
Nanopartículas Metálicas/química , Polimerização , Polímeros/química , Ouro/química , Polímeros/síntese química , Temperatura
16.
Langmuir ; 27(20): 12650-6, 2011 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-21902218

RESUMO

In this paper, we demonstrate the first hybrid suprastructure of pseudopolyrotaxanes (PPRs) on clay nanoplatelets. Simple end-modification of poly(ethylene glycol) with pyridinium (PEG-N(+)) enabled the chains to form brushlike conformation on clay surfaces. Thus, the PEG chains were able to thread into the cavities of α-cyclodextrins (α-CDs), leading to hybrid PPR hydrogels. This was very different from the unmodified PEG chains, which were absorbed onto the clay surface and thus made the PPR formation impossible. The hydrogels made of this PPR-on-clay structure displayed a dynamic modulus 1 order of magnitude higher than those of the native PPR hydrogels. Furthermore, based on the competitive host-guest interactions, such hybrid hydrogels showed fully photoreversible sol-gel transition after a competitive guest containing azobenzene moiety was introduced.

18.
Environ Res ; 109(8): 943-51, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19733844

RESUMO

On August 29, 2005, Hurricane Katrina made landfall near New Orleans, Louisiana, a major metroplex with petroleum industries. In response to the potential impact of the storm on air quality and to assess the exposures to toxic air pollutants of public health concern, the United States Environmental Protection Agency conducted passive monitoring of air toxics for three months, starting in late October 2005 through early February 2006, at up to 18 sites in the New Orleans area affected by Hurricane Katrina. The overall results of the passive ambient monitoring are summarized with the concentrations for the twenty-nine observed volatile organic chemicals, which include benzene, toluene, ethylbenzene, and xylenes, and the measured concentrations are compared with available health-based screening levels. The results of passive monitoring are also compared with those of the collocated canister sampling at one of the sites. The overall results showed that the outdoor levels of atmospheric volatile organic chemcals in the post-Katrina New Orleans area were very low and far below the available screening levels. The results also confirm the effectiveness of passive monitoring in a large geographical area where conventional methods are not feasible, electrical power is not available, and the need for sampling is urgent, as in the aftermath of natural disasters and other catastrophes.


Assuntos
Poluentes Atmosféricos/análise , Tempestades Ciclônicas , Compostos Orgânicos Voláteis/análise , Monitoramento Ambiental , Louisiana , Controle de Qualidade
19.
Environ Monit Assess ; 128(1-3): 369-79, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17057989

RESUMO

In the summer of 2003, ambient air concentrations of volatile organic compounds (VOCs) were measured at 12 sites within a 3-km radius in Deer Park, Texas near Houston. The purpose of the study was to assess local spatial influence of traffic and other urban sources and was part of a larger investigation of VOC spatial and temporal heterogeneity influences in selected areas of Houston. Seventy 2-h samples were collected using passive organic vapor monitors. Most measurements of 13 VOC species were greater than the method detection limits. Samplers were located at 10 residential sites, a regulatory air monitoring station, and a site located at the centroid of the census tract in which the regulatory station was located. For residential sites, sampler placement locations (e. g., covered porch vs. house eaves) had no effect on concentration with the exception of methyl tertiary-butyl ether (MTBE). Relatively high correlations (Pearson r > 0.8) were found between toluene, ethylbenzene, and o,m,p-xylenes suggesting petroleum-related influence. Chloroform was not correlated with these species or benzene (Pearson r < 0.35) suggesting a different source influence, possibly from process-related activities. As shown in other spatial studies, wind direction relative to source location had an effect on VOC concentrations.


Assuntos
Compostos Orgânicos/análise , Sensibilidade e Especificidade , Texas , Volatilização
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